March 1, 2011, marked the centennial of the Weeks Act — the "organic act" of the eastern national forests. Signed into law by President William Howard Taft, the Weeks Act permitted the federal government to purchase private land in order to protect the headwaters of rivers and watersheds in the eastern United States and called for fire protection efforts through federal, state, and private cooperation. It has been one of the most successful pieces of conservation legislation in U.S. history. To date, nearly 20 million acres of forestland have been protected by the Weeks Act, land that provides habitat for hundreds of plants and animals, recreation space for millions of visitors, and economic opportunities for countless local communities. As one historian has noted, "No single law has been more important in the return of the forests to the eastern United States" than the Weeks Act.